Push-pull wheeled luggage

ABSTRACT

A wheeled luggage is configured to be pushed or pulled using a handle attached to the wheeled luggage. The wheeled luggage has a main luggage body with a plurality of fixed wheels and one or more swingable wheels in front of the plurality of fixed wheels. Each swingable wheel has an elongated neck attached to a front lower portion of the main luggage body, with a backward tilt due to a higher ground clearance in the front lower portion. This backward tilt enables a user to push the wheeled luggage ergonomically by applying force to the handle.

BACKGROUND

This invention generally relates to luggage. In particular, the invention relates to a novel wheeled luggage that reduces the user's burden of lifting a portion of the wheeled luggage during transportation.

Wheeled luggage is a common method of carrying items for shippers and travelers. One common type of wheeled luggage is a “pullman” case. There are several variations of pullman cases. One type of pullman cases has two fixed wheels located in the bottom-rear portion and a pair of plastic legs in the bottom-front portion of the case. This type of pullman case also has a handle or a strap located in the front portion of the case. A user is required to “pull” the case by lifting the front portion of the case and pulling the case forward. The pullman case can either have a solid or flexible casing. One disadvantage of the pullman case is that the user has to lift the front portion of the case with a handle and then pull the case forward, which requires a directly proportional amount of pulling force relative to the weight of the case. Therefore, for pullman cases, increased weight of luggage requires a proportionally increased amount of pulling force from the user.

Another common type of pullman case has four wheels at the bottom of the case. They are designed to be pulled like a wagon with a handle or a strap in the front portion of the case. In order to pull the case ergonomically, the handle or the strap of the four-wheeled pullman is diagonally upward from the front portion of the case because a user is typically taller than the case. A Newtonian physics force diagram for the required diagonally-upward force suggests that the user is essentially lifting a portion of the weight of the case (i.e. a vertical vector component from the diagonally upward vector representing the net force). Therefore, heavier pullman cases assert substantial strain on the user's arm during transportation. As a real-world example, this drawback is apparent to a user in with a heavy pullman-type luggage at a large airport, where the user may be required to roll the luggage across hundreds or thousands of yards.

Therefore, a novel wheeled luggage which substantially reduces the stress on a user's arm is highly desirable.

SUMMARY

A wheeled luggage case is configured to be pushed and pulled by a user using a handle attached to the luggage case. The luggage case comprises a main luggage body with a higher ground clearance in front relative to rear of the main luggage body, wherein the main luggage body is configured to contain items inside, a plurality of fixed wheels located at a rear lower portion of the main luggage body, wherein each fixed wheel of the plurality of fixed wheels stabilizes a straight path movement, and a plurality of swingable wheels located in front of the plurality of fixed wheels, wherein an elongated neck for each swingable wheel attached to a front lower portion of the main luggage body provides the higher ground clearance relative to the plurality of fixed wheels at the rear lower portion of the main luggage body, thereby tilting the main luggage body backward when the plurality of fixed wheels and the plurality of swingable wheels are touching a flat surface.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a user pushing a wheeled luggage in accordance with one or more embodiments of the invention.

FIG. 2 shows a user pulling a wheeled luggage in accordance with one or more embodiments of the invention.

FIG. 3 shows a bottom portion of a wheeled luggage in accordance with one or more embodiments of the invention.

FIG. 4 shows a bottom portion of a wheeled luggage in accordance with one or more embodiments of the invention.

FIG. 5 shows a laid-down side view of a wheeled luggage in accordance with one or more embodiments of the invention.

FIG. 6 shows a zoomed-in view of a swingable wheel located at a bottom-front portion of a wheeled luggage in accordance with one or more embodiments of the invention.

DETAILED DESCRIPTION

Specific embodiments of the invention will now be described in detail with reference to the accompanying figures. Like elements in the various figures are denoted by like reference numerals for consistency.

In the following detailed description of embodiments of the invention, numerous specific details are set forth in order to provide a more thorough understanding of the invention. However, it will be apparent to one of ordinary skill in the art that the invention may be practiced without these specific details. In other instances, well-known features have not been described in detail to avoid unnecessarily complicating the description.

In general, embodiments of the invention relate to an apparatus for carrying items in a luggage. More specifically, embodiments of the invention relate to a wheeled luggage which can be used for a “push mode” and a “pull mode” by the user using a handle attached to the wheeled luggage.

Furthermore, embodiments of the invention enable the user to move the wheeled luggage in a push mode with significantly less effort than in a pull mode. More specifically, the invention alleviates the user from lifting a portion of the weight of the wheeled luggage by tilting the luggage backward (i.e. towards the user) and incorporating one or more “swingable” front wheels in lower front portion of the luggage.

In one embodiment of the invention, each swingable wheel is configured to rotate horizontally around a neck of the swingable wheel attached to a bottom portion of the wheeled luggage. The tilting of the wheeled luggage is achieved by using an elongated neck for each swingable wheel, thereby creating a higher front ground clearance relative to a lower rear ground clearance provided by fixed rear wheels for the wheeled luggage.

In one embodiment of the invention, an elongated neck of a swingable wheel includes a triangular neck portion which enables the swingable wheel to make a perpendicular contact to a flat surface. Without the triangular neck portion, the elongated neck forms a perpendicular angle with a bottom surface of the wheeled luggage but undesirably forms an obtuse and an acute angles with the flat surface. A non-orthogonal contact between the swingable wheel and the flat surface hampers the user from pushing the wheeled luggage efficiently because the horizontal “swing” or directional movements of the swingable wheel is hampered by uneven gravitational pressure to the swingable wheel. With the triangular neck portion, gravitational pressure is generally more evenly applied to the swingable wheel, thereby making the swingable wheel easier to orient to a certain direction based on the user's directional force applied to a luggage handle.

FIG. 1 shows a user (111) pushing a wheeled luggage (103) with a pair of fixed rear wheels (106) and at least one swingable front wheel (113) in accordance with the invention. This activity is defined as the “push mode.”

In one or more embodiments of the invention, the pair of fixed rear wheels (106) provide linear stability to movement of the wheeled luggage (103) and a swingable front wheel (113) provides a directional guidance to the wheeled luggage (103) depending on the user's applied force on a handle (102) attached to the wheeled luggage (103). It is important to note that the wheeled luggage (103) is tilted backward (i.e. towards the user (111)) because an elongated neck creates a higher front clearance than a rear ground clearance created by the pair of fixed rear wheels (106). The elongated neck comprises a triangular neck portion (104) which enables the swingable front wheel (113) to make a perpendicular contact (6) to a flat surface. The elongated neck further comprises an additional neck portion (105) which contains the swingable front wheel (113). The additional neck portion (105) is horizontally swingable by rotating around a vertical axis contained in the elongated neck, depending on a directional force applied by the user (111) to the handle (102).

The perpendicular contact (6) to the flat surface enabled by the triangular neck portion (104) is important because the perpendicular contact (6) enables generally even gravitational pressures on the swingable front wheel (113), which reduces rotation-hampering forces to the swingable front wheel (113) based on the directional force applied by the user (111).

Continuing with FIG. 1, there is an engineering motivation for tilting the wheeled luggage (103) backward (i.e. towards the user (111)) in accordance with the invention. If the wheeled luggage (103) were not tilted backward and instead remained orthogonal to the flat surface, it is ergonomically difficult to apply any horizontal force F_(h1) (107) to the wheeled luggage (103) using the handle (102) without tipping the wheeled luggage (103). A simple vector component diagram of a net force provided by the user, F_(u1) (109), shows a clear advantage of tilting the wheeled luggage (103) backward when the user decides to apply a diagonal forward-downward force, F_(u1) (109), to the handle. A simple Newtonian physics vertical and horizontal vector analysis shows that a horizontal vector, F_(h1) (107), provides a forward push to the wheeled luggage (103). A vertical vector, F_(v1) (108), on the other hand, provides a downward force mostly to the pair of fixed rear wheels (106), thereby helping stability of the wheeled luggage (103) when the user (111) applies F_(u1) (109).

An inherent advantage of the present invention comes from the push mode of wheeled luggage (103). Unlike a pull mode, in which the user is forced to lift a portion of the weight of the wheeled luggage, the push mode benefits from an inherent advantage in laws of physics. By applying the diagonal forward-downward force (i.e. push mode) instead of a forward-upward force (i.e. pull mode), the user leverages gravity and does not have to lift a portion of the weight of the wheeled luggage. Over long distances, this force advantage results in superior usability and efficiency for movement of the wheeled luggage. Ease of movement of the wheeled luggage during the push mode is a key feature of the invention.

FIG. 2 shows a user (211) lifting a front swingable wheel (206) from a surface and pulling a wheeled luggage (203) using a pair of fixed rear wheels (210) by applying a forward-upward force, F_(u2) (209), in accordance with the invention. This activity is defined as the “pull mode”.

In one or more embodiments of the invention, the pair of fixed rear wheels (210) provide a linear stability to the movement of the wheeled luggage (203). Unlike the push mode, the pull mode requires the user (211) to apply the forward-upward force, F_(u2) (209), to a handle (202) which necessitates the user (211) to lift a portion of the weight of the wheeled luggage (203).

A simple Newtonian physics vector diagram (207, 208, 209) demonstrates this added burden to the user (211) for the pull mode. The net force applied by the user (211) is illustrated by a vector, F_(u2) (209), which can be broken down into components, a horizontal vector, F_(h2) (207), and a vertical vector, F_(v2) (209). The horizontal vector, F_(h2) (207) is responsible for pulling the wheeled luggage (203) forward. The vertical vector, F_(v2) (208), essentially requires the user (211) to lift up a portion of the weight of the wheeled luggage (203). In essence, lifting up the portion of the weight of the wheeled luggage (203) is inefficient and unnecessary (i.e. in light of the push mode described for FIG. 1), but it is an inherent force required in the pull mode.

Continuing with FIG. 2, although the pull mode requires more effort to the user (211), it is a conventional mode of moving wheeled luggages. The wheeled luggage (203) in accordance with the invention provides this additional mode of operation for further user convenience. A Newtonian physics-based force efficiency provided by the novel push mode as described in FIG. 1 and the flexibility of the conventional pull mode as described in FIG. 2 give the present invention great utility and convenience to the user (211).

FIG. 3 shows a bottom surface of a wheeled luggage (303) in accordance with one or more embodiments of the invention. A pair of fixed rear wheels (304) provides linear stability to the wheeled luggage (303) for both push and pull modes as described in FIG. 1 and FIG. 2. A swingable wheel (301) is located in front of the pair of fixed rear wheels (304). In one or more embodiments of the invention, the swingable wheel (301) is roughly equidistant from each fixed rear wheel (304) and forms a geometrical configuration similar to a tricycle.

Continuing with FIG. 3, the term “swingable” defines the horizontal circular movement of the swingable wheel (301), as shown by arrows (302). The swingable wheel (301) can be attached to a front portion of the wheeled luggage (303) by riveting, drilling, or bolting an elongated neck (305) into the bottom surface of the wheeled luggage (303). This tricycle-like configuration with the elongated neck (305) containing an axis of rotation for the swingable wheel (301) is a preferred embodiment of the invention.

FIG. 4 shows a bottom surface of a wheeled luggage (403) in accordance with one or more embodiments of the invention. A pair of fixed rear wheels (404) provides linear stability to the wheeled luggage (403) for both push and pull modes as described in FIG. 1 and FIG. 2. A pair of swingable wheels (405) is located in front of the pair of fixed rear wheels (404). In one or more embodiments of the invention, this four-wheel configuration is optimal for supporting a heavier weight of the wheeled luggage (403) compared to the tricycle-like configuration of the wheeled luggage (303) described in FIG. 3.

Continuing with FIG. 4, the term “swingable” defines the horizontal circular movements of the pair of swingable wheels (405), as shown by arrows (402). The pair of swingable wheels (405) can be attached to a front portion of the wheeled luggage (402) by riveting or drilling elongated necks (401) into the bottom surface of the wheeled luggage (403).

FIG. 5 shows a laid-down view of a wheeled luggage (501) in accordance with one or more embodiments of the invention. A handle case holder (504) typically houses a retractable handle (505), from which a user exerts pushing or pulling force to the wheeled luggage (501). The handle case holder (504) and the retractable handle (505) are typically made of metal of plastic. A pair of fixed rear wheels (503) can be either held together by rear wheel necks which are typically riveted, drilled, or bolted on to a lower rear portion of the wheeled luggage (501). One or more swingable wheels (502) is also typically riveted, drilled, or bolted on to a lower front portion of the wheeled luggage (502).

FIG. 6 shows a zoomed-in view of a swingable wheel (604) located at a lower front portion of the wheeled luggage (601) in accordance with one or more embodiments of the invention. A triangular neck portion (602) of an elongated neck (602, 603) enables the swingable wheel (604) to make a perpendicular contact to a flat surface (600). This perpendicular contact creates a generally even gravitational pressure on the swingable wheel (604), thereby reducing direction-hampering forces which would otherwise be present if the swingable wheel (604) makes a non-perpendicular contact to the flat surface (600).

The elongated neck (602, 603) also gives the wheeled luggage (601) a higher ground clearance in the front than the rear, creating a backward tilt necessary for the user to apply a diagonal forward-downward force to a handle to propel the wheeled luggage for the push mode. A lower portion of the elongated neck (603) is horizontally swingable along a vertical axis of rotation contained within the elongated neck (602, 603). This horizontal, circular swinging action enables the swingable wheel (604) configured to roll within the lower portion of the elongated neck (603) to swing around the vertical axis of rotation depending on a directional force applied by the user.

While the invention has been described with respect to a limited number of embodiments, those skilled in the art, having benefit of this disclosure, will appreciate that other embodiments can be devised which do not depart from the scope of the invention as disclosed herein. Accordingly, the scope of the invention should be limited only by the attached claims. 

1. A three-wheeled luggage case configured to be pushed and pulled by a user using a handle attached to the three-wheeled luggage case, the three-wheeled luggage case comprising: a main luggage body with a higher ground clearance in front relative to rear of the main luggage body, wherein the main luggage body is configured to contain items inside and the main luggage body is tilted backward by an elongated neck attached to a lower portion of the main luggage body and a swingable wheel; a pair of fixed wheels located at a rear edge of the lower portion of the main luggage body, wherein each fixed wheel of the pair of fixed wheels stabilizes a straight path movement and a portion of each fixed wheel is configured to roll inside a corresponding wheel well carved into the main luggage body; the swingable wheel located in front of the pair of fixed wheels, wherein the swingable wheel is equidistant from the pair of fixed wheels and the swingable wheel is configured to swing around an axis of rotation; and the elongated neck comprising a triangular neck portion and an additional neck portion, wherein the triangular neck portion forms a perpendicular angle between the axis of rotation for the swingable wheel and a flat surface, and wherein the perpendicular angle between the axis of rotation for the swingable wheel and the flat surface is specifically used to optimize rotating forces to the swingable wheel for easy-swinging motions.
 2. The three-wheeled luggage case of claim 1, wherein the main luggage body tilted backward means that the main luggage body is tilted towards the user standing behind the three-wheeled luggage case because of the higher ground clearance in front due to the elongated neck attached to the lower portion of the main luggage body and the swingable wheel.
 3. The three-wheeled luggage case of claim 1, wherein the swingable wheel located in front of the pair of fixed wheels is configured to change its direction freely around the axis of rotation of the swingable wheel depending on a direction of a force applied by the user.
 4. The three-wheeled luggage case of claim 1, wherein each fixed wheel of the pair of fixed wheels is located partially inside the corresponding wheel well at each corner of the rear edge of the lower portion of the main luggage body.
 5. The three-wheeled luggage case of claim 1, wherein the swingable wheel enables the user to push the three-wheeled luggage case forward in any direction by applying a diagonal forward-downward force on the handle of the three-wheeled luggage case and wherein the pair of fixed wheels located at the rear edge of the lower portion of the main luggage body provides a straight-line stability.
 6. The three-wheeled luggage case of claim 1, wherein the three-wheeled luggage case can be pulled by the user by substantially tilting the main luggage body towards the user, thereby detaching the swingable wheel from the flat surface and relying only on the pair of fixed wheels for pulling movement of the wheeled luggage case.
 7. (canceled)
 8. The three-wheeled luggage case of claim 1, wherein the perpendicular angle between the axis of rotation of the swingable wheel and the flat surface accommodates smoother operation of the three-wheeled luggage case when the user applies a diagonal forward-downward force on the handle of the three-wheeled luggage case.
 9. A wheeled luggage case configured to be pushed and pulled by a user using a handle attached to the wheeled luggage case, the wheeled luggage case comprising: a main luggage body with a higher ground clearance in front relative to rear of the main luggage body, wherein the main luggage body is configured to contain items inside and the main luggage body is tilted backward by a plurality of elongated necks attached to a lower portion of the main luggage body and a plurality of swingable wheels; a plurality of fixed wheels located at a rear bottom portion of the main luggage body, wherein each fixed wheel of the plurality of fixed wheels stabilizes a straight path movement and a portion of each fixed wheel configured to roll inside a corresponding wheel well carved into the main luggage body; a plurality of swingable wheels located in front of the plurality of fixed wheels; wherein each of the plurality of swingable wheels is configured to swing around an axis of rotation; and the plurality of elongated necks, each comprising a triangular neck portion and an additional neck portion, wherein the triangular neck portion forms a perpendicular angle between the axis of rotation for each of the plurality of swingable wheels and a flat surface, and wherein the perpendicular angle between the axis of rotation for each of the plurality of swingable wheels and the flat surface is specifically used to optimize rotating forces to each of the plurality of swingable wheels for easy-swinging motions.
 10. The wheeled luggage case of claim 9, wherein the main luggage body tilted backward means that the main luggage body is tilted towards the user standing behind the wheeled luggage case because of the higher ground clearance in front due to the plurality of elongated necks attached to the lower portion of the main luggage body and the plurality of swingable wheels.
 11. The wheeled luggage case of claim 9, wherein each of the plurality of swingable wheels located in front of the plurality of fixed wheels is configured to change its direction freely around the axis of rotation for each of the plurality of swingable wheels depending on a direction of a force applied by the user.
 12. The wheeled luggage case of claim 9, wherein each fixed wheel of the plurality of fixed wheels is located partially inside the corresponding wheel well at the rear bottom portion of the main luggage body.
 13. The wheeled luggage case of claim 9, wherein the plurality of swingable wheels enables the user to push the wheeled luggage case forward in any direction by applying a diagonal forward-downward force on the handle of the wheeled luggage, and wherein the plurality of fixed wheels located at the rear bottom portion of the main luggage body provides a straight-line stability.
 14. The wheeled luggage case of claim 9, wherein the wheeled luggage case can be pulled by the user by substantially tilting the main luggage body towards the user, thereby detaching the plurality of swingable wheels from the flat surface and relying only on the plurality of fixed wheels for pulling movement of the wheeled luggage case.
 15. (canceled)
 16. The wheeled luggage case of claim 9, wherein the perpendicular angle between each axis of rotation of the plurality of swingable wheels and the flat surface accommodates smoother operation of the wheeled luggage case when the user applies a diagonal forward-downward force on the handle of the wheeled luggage case.
 17. An elongated neck for a swingable wheel located at a lower front portion of a tilted wheeled luggage, the elongated neck comprising: a separate triangular neck portion for each swingable wheel, wherein a top surface of the separate triangular neck portion is attached to a bottom surface of the titled wheeled luggage and wherein the separate triangular neck portion enables an axis of rotation for the swingable wheel to make a perpendicular angle with a flat surface for the tilted wheeled luggage, and wherein the perpendicular angle between the axis of rotation for the swingable wheel and the flat surface is specifically used to optimize rotating forces to each of the plurality of swingable wheels for easy-swinging motions; and an additional neck portion attached to a bottom surface of the triangular neck portion, wherein the additional neck portion configured to provide sufficient height to the tilted wheeled luggage for a higher front ground clearance than a rear ground clearance.
 18. (canceled)
 19. (canceled) 